On Mon, Nov 18, 2013 at 05:38:18PM +0100, Daniel Vetter wrote: > On Mon, Nov 18, 2013 at 5:31 PM, Thierry Reding > <thierry.reding@xxxxxxxxx> wrote: > >> Note that there's already a bit of abstraction for i2c over dp aux, but > >> imo that's at the wrong level. At least reading through i915, gma500 and > >> radeon code there's a lot more we could share with just a dp aux helper > >> library (which then implements useful stuff on top of it). > > > > I have some difficulty envisioning how the helper code can work without > > some sort of driver-specific ops implementation. Currently the helpers > > only use a snapshot of the DPCD to extract information. Eventually we'll > > be bound to modify the DPCD, so some method of writing it back (or a > > subset of it) will be needed. Otherwise the scope of the helper library > > will be somewhat limited. > > > > Once we have the callbacks, the current helpers could be reworked to not > > use a buffer, but rather an "AUX channel object" and access the > > registers directly. If there are concerns about performance, it could > > possibly be implemented as a sort of cache, too. That would make it fast > > to query the status. I don't think it'll be worth the added complexity, > > though. > > Oh, my idea is that the dp aux driver callback would at the level of > the intel_dp_aux_ch function in i915/intel_dp.c (gma500 and radeon > have something very similar). That alone would allow us to share a > considerable amount of code. Should have been a bit clearer, I've > discussed this in a bit more detail with Alex many moons ago ... Yeah, that's similar to what I had in mind. I think we may need something slightly more complex, though. We want to support both AUX as well as I2C over AUX transactions, so we'll probably need to add a mode argument. I was thinking about adding a dp_aux_msg structure in order to keep the argument list to a reasonable length. Thierry
Attachment:
pgpMMn3cUDEYo.pgp
Description: PGP signature
_______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
